Given the circumstances, it's then critical for publishers to eke out every penny from their mobile inventory. Here are a six suggestions culled from industry experts to help them do it:

1. Hire a mobile specialist
Until recently, mobile inventory was often thrown in at the end of sales deals, sold without much thought put in. But times have changed. Publishers serious about selling mobile should hire a mobile specialist dedicated to the medium, according to Undertone co-founder Eric Franchi. Mr. Franchi told Ad Age that a mobile specialist can help a publisher articulate the value of their mobile inventory, elevating mobile from throw-in to a distinct offering. Mr. Franchi added that marketers with big mobile budgets now employ their own mobile specialists, so a "peer" on the publisher side can help capture the dollars they have to spend. "This person can target the folks who own mobile budgets and come up with some cool ways to deploy them," he said.

2. Attribute across devices
One of the main problems with mobile advertising is that consumers buy less on their phones than they do on desktops, making it difficult for advertisers to justify allocating more dollars there. But just because consumers buy less on mobile doesn't mean the ads aren't working. It is quite possible for a consumer seeing an ad for a product to buy it later on desktop. While that journey may be difficult to track, companies like Tapad are working on the problem, allowing for cross-device attribution tracking. Publishers should preach the adoption of such technology to buyers, or they'll never be compensated for the true worth of their inventory.

3. Design responsively
Though it may now have reached buzzword status, responsive design can have serious revenue implications when it comes to mobile revenue. The standard mobile ad unit -- a 300x50 bar that manages to appeal mostly to fat fingers -- is nearly impossible to message with. With a responsive design, one that renders a publisher website to fit the device it's accessed on, a 300x250 desktop ad can neatly fold into a mobile design. Not only will that give marketers more space to message with but, according to Mr. Franchi, it will also put less strain on advertiser resources, which now are spread thin creating seperate ads for mobile.

4. Package across mediums
Starting a sales conversation with a mobile only or desktop only pitch is a great way for publishers to limit the potential ad dollars spent with them. By packaging mobile inventory with desktop inventory though, they can dip into both budgets. Facebook, said Mr. Franchi, understood this and set its ads to run cross-screen by default. "It turned mobile from a liability into a strength," he said. "The idea is let's have publishers take a page out of that book."

5. Sell targeted mobile inventory
It's well known that the cookies don't work on mobile, but that doesn't mean that behavioral targeting doesn't either. Big companies like Facebook and Pandora can target mass audiences on mobile, because they see them logged in on two screens. For everyday publishers not privy to such massive audiences, there are products that can help them sell behavioral targeting on mobile, sans cookies. Drawbridge currently offers this capabiltiy as a managed service is developing a tool for publishers to do it themselves. TapAd has such a tool in beta.

6. Seek alternate revenue sources
"If you're speaking about CPM, you're speaking the wrong language," said Uyen Tieu, co-founder and CRO of Rumble, a publisher focused mobile technology company. Instead of mobile banner ads, Ms. Tieu said, publishers should try to capture mobile revenue via a variety of other methods, including content syndication with platforms such as Taboola, affiliate links leading back to ecommerce sites like Amazon and deals with search companies to use their engines in exchange for a piece of the action. "Just thinking about how you make up the difference," said Ms. Tieu, "Putting classic banner ads at the bottom is not going to get you there at all."